The main item of interest isn't the ability to make the parts from plastic [which aren't actually functional], but the ability to take the 3-D printed plastic part made from the correct polymer & use it as the "form" in a lost foam casting process to make untraceable high resolution metal parts very inexpensively.

I know guns are fascinating, but I do wish design magazines (and Pop Mech and Pop Sci) would lean in the direction of fewer killing machines. We are a very violent people, and I fear we will reap the whirlwind.

OTOH, Making your own machine gun has got to be a legal issue...regardless of how much fun it is. Making your own brass knuckles will get you into legal trouble.

If your contribution to humanity is 3D home-made weapons. Try to balance your karma by contributing to some good cause.

"Plastics have been used in firearms for producing things like grips, but they haven't much been tapped for more structural components because of durability and integrity concerns and because, well, there are some pretty serious safety implications if the manufacturing process backfires."

Actually, plastics have been used in firearm structures for 30 years. Glock produced the first polymer framed pistols back in 1982. Many companies have incorprated plastics into the frames of their pistols. While many parts still need to be made of steel, plastics are more than strong enough to be used in a pistol frame.

I new this would get the anti's worked up. Yes the lower reciever is the "liscened" part, you can buy all other components but need a FFL to buy the lower. But in reality you can buy 80% finished lowers without a FFL and finish machining the lower with a dremel tool. Oh No pretty scary hey Anti's. The question is when is the "lower" a Lower, a hunk of aluminum the same size is not.

You can't make an "Automatic" Lower like previous comment, you would need an M16 bolt and trigger mechanism ... But did you know if i take a semi-auto lower and drill one hole in it in a certain spot it is "ILLEGAL" which seems to defy logic, but the ATF could arrest you.

And the plastic gun thing cracks me up .. are they going to make plastic bullets and fake gunpowder as well so they can't be detected .. gimme a break

Actually, they do have PLASTIC bullets. We used to shoot them in our 50cal machine guns for training people on how to operate the machine gun. They always caught the firing range on fire and the fire department would have to come shut the range down!LOL!

Police use rubber bullets for riot control. We actuallt shot each other with these as an INITIATION!!

99% of the population are unable to create anything in engineering-level CAD (such as Solidworks) and/or have the engineering knowledge and experience to download part files, modify parts and print them via a 3D printer which very few people personally own. I'm not concerned that thousands of people will now be able to make their own guns. Besides, guns are readily available to criminals and non criminals, such as at your local sporting goods store and gun shows.

Having 3D printer which we use daily, and with experience around M-16/AR-15 since 1972 and owning several current model AR-15s, I am very familar with the desing an limitations of both. A lower receiver never comes into contact with the round, so the stress on a lower receiver is minimal. Sure, the lower receive holds the magazine, trigger housing and assembly, and buffer & spring assembly, but none of these surfaces ever contact the round, aka, bullet.

The upper receiver (barrel, chanmber, bolt & bolt carrier) are the parts which must be made of metal becuase they are they are the components which contact the round and must take the stress, heat, and pressure of the round when it is fired. If one looks into the history of the design of the AR-15, that was one of the objectives for the combination of the upper receiver and lower receiver.

I could fire a round with a plastic lower receiver, but there is no way I would try to fire a round with a plastic upper receiver.

Instead of wringing your hands about the making of guns, why aren't you more upset at a culture that has endevoured to eliminate the discussion of right and wrong. Our schools are not allowed to make "value judgements" and thus teach our kids that there is really no such thing as right and wrong. When we don't have any idea of right and wrong then I can do anything I want to do without consequence. And we are seeing the consequence of anarchistic practices.

In the US, the law is that an individual can produce a firearm for their own use without any permits as long as it is not a full-auto firearm. It does not preclude that individual from later selling that weapon, but if sold it must have the makers name and a serial number. An individual also cannot make a firearm for another person, only for personal use.

With the advent of small, affordable CNC machines the capability of making a veriety of productsm including firearms has been in the hands of hobbiests for a number of years. One could develop a rather capable CNC machine shop for less than $10,000 US, 3D printing is just catching up.

And as was statred previously, 40,000 die every year in car realted deaths and we take no notice, a few die in a aircraft accident and we all respond in horror, and some are killed with firearms and we want them banned. Maybe we would be better off if we spent some time evaluating why all these events happen and fixing the problems rather than the symptoms. Do we eliminate cars because people are killed by cars? Do we eliminate pillows because some are smothered by pillows? Do we collect all the knives because someone is stabbed?

A 3d printed lower for an AR is a really cool thing, doesn't bother me a bit. Now a particle beam weapon made from surplus microwave oven magnetrons, or an oxy-acetylene powered gatling gun firing ceramic flechettes - those might be cause for alarm...

Virtual Reality (VR) headsets are getting ready to explode onto the market and it appears all the heavy tech companies are trying to out-develop one another with better features than their competition. Fledgling start-up Vrvana has joined the fray.

A Tokyo company, Miraisens Inc., has unveiled a device that allows users to move virtual 3D objects around and "feel" them via a vibration sensor. The device has many applications within the gaming, medical, and 3D-printing industries.

While every company might have their own solution for PLM, Aras Innovator 10 intends to make PLM easier for all company sizes through its customization. The program is also not resource intensive, which allows it to be appropriated for any use. Some have even linked it to the Raspberry Pi.

solidThinking updated its Inspire program with a multitude of features to expedite the conception and prototype process. The latest version lets users blend design with engineering and manufacturing constraints to produce the cheapest, most efficient design before production.

Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.